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Running the gauntlet: regional movement patterns of Manta alfredi through a complex of parks and fisheries.

Germanov ES, Marshall AD - PLoS ONE (2014)

Bottom Line: A better understanding of the habitat use and movement patterns of manta rays in Indonesia is needed in order to employ effective conservation measures.These long-range manta ray movements suggest connectivity between M. alfredi populations in neighboring islands and raise concerns about the future management of regional populations.It is recommended that a national conservation strategy be developed to protect the remaining populations in the country.

View Article: PubMed Central - PubMed

Affiliation: Marine Megafauna Foundation, Truckee, California, United States of America.

ABSTRACT
Manta rays (Genus Manta) are economically important for fisheries and tourism in Indonesia. These species have been listed by the International Union for the Conservation of Nature Red List as Vulnerable to extinction; therefore, human exploitation of manta rays must be regulated. A better understanding of the habitat use and movement patterns of manta rays in Indonesia is needed in order to employ effective conservation measures. To gain better insight into the movements of Manta alfredi we used 'Manta Matcher', an online database with an integrated automated matching algorithm, to compare photographs from 2,604 encounters of M. alfredi collected by recreational divers and dive operators throughout Indonesia over a nine-year period. This photographic comparison revealed that manta rays migrated between regional sanctuaries such as Nusa Penida, the Gili Islands, and the Komodo National Park (up to 450 km straight-line distance). The areas between these sanctuaries are heavily fished and trafficked by ships, and when manta rays travel through these regions they risk being fished and injured by ship strikes. These long-range manta ray movements suggest connectivity between M. alfredi populations in neighboring islands and raise concerns about the future management of regional populations. It is recommended that a national conservation strategy be developed to protect the remaining populations in the country.

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The locations of M. alfredi encounters in Indonesia submitted to Manta Matcher.Sites are numbered as follows: 1) Pulau Weh 2) Palau Sangalaki 3) Nusa Penida 4) Gili Islands 5) West Manggarai & Komodo National Park 6) Raja Ampat. (A) Connectivity area and commercial fisheries area (see Figure 2 for enlargement). (B) Region surveyed in Raja Ampat (see Figure 3 for enlargement).
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pone-0110071-g001: The locations of M. alfredi encounters in Indonesia submitted to Manta Matcher.Sites are numbered as follows: 1) Pulau Weh 2) Palau Sangalaki 3) Nusa Penida 4) Gili Islands 5) West Manggarai & Komodo National Park 6) Raja Ampat. (A) Connectivity area and commercial fisheries area (see Figure 2 for enlargement). (B) Region surveyed in Raja Ampat (see Figure 3 for enlargement).

Mentions: Understanding the migratory range of manta rays (M. alfredi) in Indonesia is particularly important, as major fisheries often occur near to marine sanctuaries. A previous study using acoustic telemetry, showed that M. alfredi (referred to then as M. birostris) exhibit considerable site fidelity through localized re-sightings within areas of the Komodo National Park [11]. This study also demonstrated that there was considerable movement (of up to approximately 33.5 km apart) between the individual sites that coincided with seasonal monsoon-shifts [11]. While this was a good preliminary effort to learn more about the habitat use of M. alfredi within the Komodo National Park, this study was spatially limited by the technology used leaving many unanswered questions. For instance, (34%) of the tagged individuals spent a minimum of 2 months and a maximum of 9 months outside of the range of the acoustic receiver array (which was set up within the park) suggesting that M. alfredi may also travel to and spend significant amounts of time in other areas [11]. Recent studies have reported M. alfredi movements greater than 380 km (straight-line distance) in places like Mozambique and Australia [5], [8], [12]–[14]. Major fishing grounds and known manta ray landing ports, Tanjung Luar, Lombok [3] and Lamakera [3], [10], are within 380 km of M. alfredi sanctuaries in West Manggarai and Nusa Penida (Figure 1). Thus it is plausible that the migratory range of M. alfredi may overlap with heavily fished areas in Indonesia.


Running the gauntlet: regional movement patterns of Manta alfredi through a complex of parks and fisheries.

Germanov ES, Marshall AD - PLoS ONE (2014)

The locations of M. alfredi encounters in Indonesia submitted to Manta Matcher.Sites are numbered as follows: 1) Pulau Weh 2) Palau Sangalaki 3) Nusa Penida 4) Gili Islands 5) West Manggarai & Komodo National Park 6) Raja Ampat. (A) Connectivity area and commercial fisheries area (see Figure 2 for enlargement). (B) Region surveyed in Raja Ampat (see Figure 3 for enlargement).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4206290&req=5

pone-0110071-g001: The locations of M. alfredi encounters in Indonesia submitted to Manta Matcher.Sites are numbered as follows: 1) Pulau Weh 2) Palau Sangalaki 3) Nusa Penida 4) Gili Islands 5) West Manggarai & Komodo National Park 6) Raja Ampat. (A) Connectivity area and commercial fisheries area (see Figure 2 for enlargement). (B) Region surveyed in Raja Ampat (see Figure 3 for enlargement).
Mentions: Understanding the migratory range of manta rays (M. alfredi) in Indonesia is particularly important, as major fisheries often occur near to marine sanctuaries. A previous study using acoustic telemetry, showed that M. alfredi (referred to then as M. birostris) exhibit considerable site fidelity through localized re-sightings within areas of the Komodo National Park [11]. This study also demonstrated that there was considerable movement (of up to approximately 33.5 km apart) between the individual sites that coincided with seasonal monsoon-shifts [11]. While this was a good preliminary effort to learn more about the habitat use of M. alfredi within the Komodo National Park, this study was spatially limited by the technology used leaving many unanswered questions. For instance, (34%) of the tagged individuals spent a minimum of 2 months and a maximum of 9 months outside of the range of the acoustic receiver array (which was set up within the park) suggesting that M. alfredi may also travel to and spend significant amounts of time in other areas [11]. Recent studies have reported M. alfredi movements greater than 380 km (straight-line distance) in places like Mozambique and Australia [5], [8], [12]–[14]. Major fishing grounds and known manta ray landing ports, Tanjung Luar, Lombok [3] and Lamakera [3], [10], are within 380 km of M. alfredi sanctuaries in West Manggarai and Nusa Penida (Figure 1). Thus it is plausible that the migratory range of M. alfredi may overlap with heavily fished areas in Indonesia.

Bottom Line: A better understanding of the habitat use and movement patterns of manta rays in Indonesia is needed in order to employ effective conservation measures.These long-range manta ray movements suggest connectivity between M. alfredi populations in neighboring islands and raise concerns about the future management of regional populations.It is recommended that a national conservation strategy be developed to protect the remaining populations in the country.

View Article: PubMed Central - PubMed

Affiliation: Marine Megafauna Foundation, Truckee, California, United States of America.

ABSTRACT
Manta rays (Genus Manta) are economically important for fisheries and tourism in Indonesia. These species have been listed by the International Union for the Conservation of Nature Red List as Vulnerable to extinction; therefore, human exploitation of manta rays must be regulated. A better understanding of the habitat use and movement patterns of manta rays in Indonesia is needed in order to employ effective conservation measures. To gain better insight into the movements of Manta alfredi we used 'Manta Matcher', an online database with an integrated automated matching algorithm, to compare photographs from 2,604 encounters of M. alfredi collected by recreational divers and dive operators throughout Indonesia over a nine-year period. This photographic comparison revealed that manta rays migrated between regional sanctuaries such as Nusa Penida, the Gili Islands, and the Komodo National Park (up to 450 km straight-line distance). The areas between these sanctuaries are heavily fished and trafficked by ships, and when manta rays travel through these regions they risk being fished and injured by ship strikes. These long-range manta ray movements suggest connectivity between M. alfredi populations in neighboring islands and raise concerns about the future management of regional populations. It is recommended that a national conservation strategy be developed to protect the remaining populations in the country.

Show MeSH
Related in: MedlinePlus